1. Field of the Invention
The present invention relates to a socket connector mounted on a mother board, and particularly to a ball grid array (BGA) socket with an improved base to reduce the height of a space formed between the socket and the mother board due to thermal stress during soldering process.
2. Description of Related Art
BGA sockets are widely used in computer industry for electrically connecting a central processing unit (CPU) to a mother board. A conventional BGA socket 9 mounted on a mother board 8 is disclosed in FIGS. 5-7. The BGA socket 9 generally comprises an insulative base 91, an array of conductive contacts 952 retained in the base 91, and a cover 92 movably mounted on the base 91. A corresponding number of solder balls 954 are attached to lower ends of the conductive contacts 952 for soldering onto the underlying mother board 8 by infrared (IR) generally. The base 91 may be warped due to thermal stress, and a space 93 is formed between a bottom surface 94 of the base 91 and the mother board 8. If the height of the space 93 is beyond allowable tolerance, the solder ball 954 could not be soldered with the mother board 8.
Hence, a BGA socket having an improved base is required to overcome the disadvantages of the conventional socket.
Accordingly, the object of the present invention is to provide a BGA socket having an improved base to reduce the height of a space formed between the socket and a mother board due to thermal stress during first and second IR soldering processes.
In order to achieve the object set forth, a BGA socket of the present inventing comprises a base, an array of conductive contacts retained in the base, a sliding cover and an actuating lever. The base includes a rectangular body and a mounting portion at a rear end thereof. The body comprises a plurality of through hole for receiving the contacts, and the mounting portion has a first surface and a second surface at the bottom. The first surface and the second surface define a vertical offset therebetween for compensating for a space between the first surface and the mother board caused by thermal stress during soldering.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.